...The sculptor led his party on the short stroll, up behind the house to a great, cottage-loaf boulder. One rock confidently balanced on another. A weather-rounded lump of resistant gneiss, a memento from our Palaeozoic yesterday. Photos were taken, videos shot. Dilworth is wearing a museum-quality tweed suit. In black and white its redness would be uninhibited: the suit is a statement of seriousness. Dilworth looks like Max von Sydow, a couple of ghouls short of an exorcism. He lifts his oversize test-tube like a lightning-conducting crucifix.

Through the album of snapshots, Hebridean comedy is revived: the poses, the funny hats - a pastiched Alpine excursion from the period when scholarship belonged to demented amateurs. Ladies in long skirts, gents who climbed the Matterhorn in hairy suits (changed for dinner, read Shelley, smoked a cigar).

Beneath and beyond the recorded jape is: process. Customised phials, rounded at both ends (with vestigial vacuum bulb burnt off), are heated by a portable gas canister. Hebridean air is trapped. The maquette that will contain it is made from polystyrene, wood, plaster. A bronze is cast and polished. A smooth helmet-shape with a lovely patina. There are apertures through which the radiant air can be examined. The bronze becomes a visor, a device that is both ancient and early contemporary. View according to choice: Sellafield or Sutton Hoo.